export type RolePalette = {
  coat: string;
  front: string;
  sleeves: string;
  legs: string;
  accent: string;
  hair: string;
};

export type RoleMeta = {
  icon: string;
  label: string;
  color: string;
};

export function roleMeta(role: string): RoleMeta {
  switch (role) {
    case "guard":
      return { icon: "🗡️", label: "Guard", color: "#e2675a" };
    case "builder":
      return { icon: "🔨", label: "Builder", color: "#5b96f0" };
    case "forager":
    case "gatherer":
      return { icon: "🌾", label: "Gatherer", color: "#6fc46a" };
    default:
      return { icon: "👤", label: role || "Villager", color: "#d9b35a" };
  }
}

export function rolePalette(role: string): RolePalette {
  switch (role) {
    case "builder":
      return {
        coat: "#3f78d3",
        front: "#76a9f8",
        sleeves: "#2f62b5",
        legs: "#56687f",
        accent: "#f0b34b",
        hair: "#4c3a2f",
      };
    case "forager":
    case "gatherer":
      return {
        coat: "#5faa59",
        front: "#91d67b",
        sleeves: "#468e45",
        legs: "#4d6e4b",
        accent: "#e6d16a",
        hair: "#5a3c2a",
      };
    case "guard":
      return {
        coat: "#b94f45",
        front: "#df7d68",
        sleeves: "#983d38",
        legs: "#4e5361",
        accent: "#d7d3c1",
        hair: "#312b29",
      };
    case "scribe":
      return {
        coat: "#805ec8",
        front: "#aa8ce4",
        sleeves: "#684aae",
        legs: "#5d5574",
        accent: "#f0df8a",
        hair: "#463245",
      };
    default:
      return {
        coat: "#c98f35",
        front: "#f0bd59",
        sleeves: "#a9772c",
        legs: "#635948",
        accent: "#7dc95e",
        hair: "#6a4028",
      };
  }
}

export type FaceVariant = {
  skin: string;
  skinShade: string;
  eyes: string;
  mouthColor: string;
  mouthWidth: number;
  brows: boolean;
  beard: boolean;
  hairStyle: "cap" | "long" | "buzz" | "bald";
};

const SKIN_TONES = [
  { skin: "#f7c89b", shade: "#eab184" },
  { skin: "#e8b483", shade: "#d89e6c" },
  { skin: "#c98a5b", shade: "#b87748" },
  { skin: "#9c6b43", shade: "#8a5a35" },
  { skin: "#7a4f30", shade: "#6a4226" },
] as const;

const EYE_COLORS = ["#23231f", "#37261a", "#2c4a6e", "#3f5d3a"] as const;
const MOUTH_COLORS = ["#7d4a39", "#94584a", "#6b3d30"] as const;
const HAIR_STYLES = ["cap", "long", "buzz", "bald"] as const;

/** Deterministic per-NPC facial features so villagers differ beyond role clothes. */
export function faceVariant(id: string): FaceVariant {
  const tone = pickByHash(SKIN_TONES, id, "skin");
  return {
    skin: tone.skin,
    skinShade: tone.shade,
    eyes: pickByHash(EYE_COLORS, id, "eyes"),
    mouthColor: pickByHash(MOUTH_COLORS, id, "mouth"),
    mouthWidth: 0.1 + hashToUnit(`${id}:mouthWidth`) * 0.08,
    brows: hashToUnit(`${id}:brows`) > 0.3,
    beard: hashToUnit(`${id}:beard`) > 0.65,
    hairStyle: pickByHash(HAIR_STYLES, id, "hairStyle"),
  };
}

function pickByHash<T>(options: readonly T[], id: string, salt: string): T {
  return options[Math.floor(hashToUnit(`${id}:${salt}`) * options.length)];
}

export function hashToUnit(input: string): number {
  let hash = 0;
  for (let index = 0; index < input.length; index += 1) {
    hash = (hash * 31 + input.charCodeAt(index)) % 1000;
  }
  return hash / 1000;
}

export function dampAngle(
  current: number,
  target: number,
  smoothing: number,
  delta: number,
): number {
  return current + signedAngleDelta(current, target) * (1 - Math.exp(-smoothing * delta));
}

export function angularDistance(current: number, target: number): number {
  return Math.abs(signedAngleDelta(current, target));
}

function signedAngleDelta(current: number, target: number): number {
  return Math.atan2(Math.sin(target - current), Math.cos(target - current));
}